The present invention relates to a method of and apparatus for delivering a fetus from a viviparous animal, particularly a human.
At one time and to a certain extent today, the use of forceps and/or the use of what is known as vacuum extraction were prevalent in certain circumstances to assist in the delivery of a fetus, both in human obstetrics and in veterinary deliveries. With respect to humans, procedures employing forceps and/or vacuum extraction attempted to extract a fetus by its head from the vagina without causing injury to the fetus or its mother. See, for example, "Williams Obstetrics", 16th Edition, Chapter 41, "Forceps Delivery and Related Technics". Both procedures are well known in the art, the foreceps procedure being traceable as far back as the thirteenth century. Although well established, both procedures subject both the mother and fetus to the risk of serious injury.
With respect to the use of forceps, although not generally acknowledged or appreciated, compression of the fetal head by the forceps is inevitable which can have a harmful effect on the brain. For example, such compression may cause circulation to be hindered and result in asphyxia and hemorrhaging. Direct injury to the cranial bones, nerves and vessels of the fetal head as well as to the brain itself can also result from the compressive use of forceps on the fetus. Also, the mother's vaginal soft tissue may be injured during a procedure in which forceps are applied to the fetus.
Use of vacuum extraction on the fetus during delivery is thought to be a cause of trauma to the fetal scalp, fetal subgaleal hematomas, fetal scalp lacerations and skin necrosis. Fetal intracranial and intraocular hemorrhages have also been reported as a result of vacuum extraction, as has damage to the vaginal soft tissue of the mother.
There are additional drawbacks to the use of forceps and vacuum extraction in human obstetrical delivery procedures, particularly when the fetal head is not visible and has progressed only to the higher positions in the vagina, such as when the fetal head is above the perineum. The use of forceps in such fetal head positions, known as mid or high forceps procedures, is rare as the procedures are extremely complicated and risky. Thus, forceps are generally applied when the fetal head is already visible during contraction, a position known as low forceps. Vacuum extraction, however, is often used when a fetus is in the higher positions. In addition to the drawbacks discussed above concerning vacuum extraction, use of vacuum extraction to a fetus located in the higher positions delays delivery since creation and application of a vacuum to the fetal head in the higher positions requires about ten minutes. This ten minute delay can be critical in the case of a fetal distress.
Because of the many negative factors described above, currently, caesarean sections are being resorted to as an alternative to forceps and vacuum extraction procedures. Caesarean section deliveries are also not without risks and complications, as is also well documented in the art.
The invention disclosed in this application avoids the drawbacks discussed above and facilitates delivery of a fetus, particularly a human fetus.